Just fitted a camera to the back of my a4.
Drilled lower plastic trim of bumper ran wiring along tow hitch wiring up into car.
Now need to connect to power permantly, tested first works fine but got bulb errors.
Thinking of using the cable for the tow hitch which i dont use instead of tapping into revsing light, its a 7 pin bosal one that swings down.
Anyone know which wire i should use?